Oil burner



W. S. GRANT nec. s, 1931.l

OIL BURNER original Filed Deo.

5, 1.927 2 Sheets-Sheet l I Patented 1.931-

UNITED, l STATES PATENT.' orrics .wmmnn s. emr, or nn'raorr. meinem,assmnon fro my D.- mmm r- DETROIT, meinem on. BURNER,

- This invention relates to oil burners for various types of furnaces orheating apparatus, the principal object being the provision` of a newand novel oilburner and particu 3 larly a fire -pot used in connectiontherew1th,g

v through the fire pot.

- and is a division of my application for Letters Patent of the UnitedStates forimprovements vin oil burners led December 5, 1927 and seriallynumbered 237,947.'A

10 Another object is the provision pf a new and novel oil 'burner potfor oil burnlng apparatus so designed and constructed as to preclude thepassagev of unvaporized fuel partlcles out of the same into thecombustion cham; .15 ber of the boiler or other apparatus for which theheat is being provided, 'and so fermedlas to provide withoutjanymechanical ald of any description'a relatively flat and wide spreadAllame. 2 Another object is the provlsion ef a burner apparatus for oilburning mechamsms so designed and constructed as not to depend upon anexcess of air su plied to the same for the complete lvaporiz'atlon ofthe oil being burned. 25 A further object is the provision of -a ir'epot for oil burning mechanism in which a refractory lining is providedand so mounted with respect to the shell of the fire pot as to quicklybrought to an incandescent condition tively long time afterdiscontinuance Aof la 'heating medium, by the prevention of heat jectsin view. 1 Y

In the accompanying drawings which illustrate a suitable embodimentofthe present invention andl in which like numerals refer to v1ews,-

Fig. 1 is a plan view of the oil burning apparatus the furnace being'shown in the horizontal section. 'l0 Fig. 2 isa side elevation of Fig.A1 partially and maintained in Such condition for a relalike partsthroughout the several diiferent 1927, serial no. 237,947.' Divided anduns appnauon ma August ao, 192s. serial No. 300,773.

in section, the muler being removed to better illustrate theconstruction of the same.

' Fig. 3 is an enlarged vertical sectional view taken on line 3.-3 ofFig. 1, lon 'tudinally -through the oil bur-ner. nozzle an centrallyFig. 4 is a vertical sectional view taken on the line 4-4 of Fig. 1 andillustratesthe form of iiame obtained by theuse of the fire potillustrated.

In the drawings is shown a conventional type of furnace 15 which may beespecially designed for use in connection withthe present lnvention orma be of the usual coal burning type which as been converted into -anoil burning type by the use of the present invention. Within the ash.pit 16 of the furnace is a fire pot designated generally in Figs. 1 and2 as. 17, which is supported from the floor of `the ash pit by thestandard 18v which adjustably engages the a er- .tured boss 19 formed onthe outer sur ace ofthe fire pot 1 7, the iire pot 17 being locked invertical adjusted position by means of the set screw 20. Integral withthe fire pot 17 is the nozzle or' venturi 21 which enters the fire potat a tangent to the interior surface thereof. Supported exteriorly ofthefurnace on the legs 22 is the stand 23' which supports the-.electricmotor 24. On 'one end of the motor 24 is secured a fan or blower 25which may be of any conventional type, but for the purpose ofillustration is shown as a centrifugal type of blower,

it being provided with-a disc r passage 26.which extends through the for27 of vthe ash` it 16and-is socketed in the outer end of t e venturi 21.The air intake for the' fan 25 extends axially from the fan casing onthe side-thereof opposite the motor 24 and receives at its free end amullier or silencer 29. This serves to mulile the sound of the airrushing through the fan and its passages and also serves to mule thenoise of combustion of the gases in the lire pot 17 which tendsto travelback through the passage 26 and'out through the fan 25.

` The oil is conducted through! theJ pipe 42 to a valve mechanism havinga .casing 43 andlthenthro'ugh the pipe 44 to another valvemechanismhaving a casing 45. From the casing the -oil is conducted through thepipe 46 to a third valve mechanism, the casing of which is indicated as47, and thence through the pipe 48 into the interior of the fan passage26, the pipe 48 terminating inv the nozzle end 49l which is providedwith a pluralityof radial openings 50 for the escape of the oil. Thepurpose of the foregoing valves which are inserted in the oil line willbe described later.

As set forth in the objects-of the present invention, the constructionherein disclosed employs no pilot light, the fire never beingextinguished, but instead, being merely checked when the room or otherspace being heated has reached a desired maximum temperature, themechanism being constructed to provide a high and'low fire. It isobvious that in attaining such a result the air and the fuel being fedto the mechanism will at no time be completely shut ofi', but that` inchanging from high to low fire a lesser amount of air and o1l willnecessarlly have to be fed to the mechanism than for high fireconditions. My method of controlling the air is to provide the fan 25 ofsuch capacity that at full speed of the motor 24 the desired amount ofair for high fire conditions is being fed to the burner, and I prefer toallow the motor 24 to run at a constant speed and to reduce the amountof air bein passed by the same to the burner for low re conditions bythrottling the amount of air which the fan 25 may draw into the same. Iaccomplish this result by positioning a butterfly valve 51 on the shaft52 within the intake passage 28 of the fan 25 and securing to the upperend of the shaft 52 above the passage 28 a lever 53. Rotatably securedto the shaft `52 above the lever 53 is a second lever member 54 providedwith a slot 55 as indicated in Fig. l. The screw 56 projects downwardlythrough the slot and threadedly engages the lever` 53 and thereby locksthe levers 53 28 I provide a third lever 57 secured thereto,

the free end of the lever being provided with a screw 58 which isa-dapted'to bear against the boss 59 formed on the lower surface of thecasing 28 to control the low fire or minimum volume of air being passedthrough the fan 25, the screw 58 being threaded inwardly or outwardly toregulate the positionof the butterfly valve 51 for this condition andthus determining the amount of space between the edges of the butterflyvalve 51 .same into the pipe 44. A needle valve provided with a suitableindicating and controlling head 66 cooperates with the valve 63 to limitthe amount of oil which may flow through the openin 63 under theconstant head provided for y the supply reservoir, this serving toregulate the amount of fuel flowing to the burner for high fireconditions when the maximum amount of 'oil is being used. A suitablepointer 67 is preferablyprovided in conjunction with the control head 66for visual location of the needle valve 65 with respect to the opening63. The oil from the pipe 44 flows'through the solenoid controlled valve45 which is connected in series with the solenoid valve 62 for the airsupply .fan and the supply of current to both of which is controlled byone or more suitable thermostats (not shown) located in the room orrooms. heated by the furnace, as will be readily understood. The valvemember 45 is so constructed that when the main flow of oil through thesame for high 4fire conditions is shut off upon operation of thesolenoid, sufficient oil is by-passed past the valve to the pipe 46 totake care of low fire conditions, as is fully explained in my previouspatent application above referred to.

As this far described, the mechanism for providing a maximum and minimumamount of oil and air has been explained, it being understood of course,that the solenoids 73 and 62 are so controlled as to furnish a maximumamount of air for the maximum amount of oil and vice versa. Theconstruction of the lire pot and burner nozzle and venturi will now bedescribed.

As shown best in Figs. 3 and 4, the fire pot comprises a cup-shapedmetal part or por tion 76 and a refractor lining 77 conforming in shapeto the port1on'76, the refractory dished upper surface of the diaphragm78 is shown as formed Complementary to a substantially spherical surfaceand as receding from a thin inner edge thereof in an upwardly curvedmanner,-the bottom of this flange being shown as flat and as disposed insubstantially the same plane as a circular upper edge of cup 76. Iprefer to so form a cylindrical wall and bottom wall of the lining 77with respect ito the corresponding walls of the cup 76, that when thesetwo Vaseline? parts are in cooperative relationship a dead air spacesuch as 79 is formed between the ad]acent walls of the same, this beinan important feature as will be later described. As previouslydescribed,the ire 'nozzle or 'venturi is formed integral with the rtion 76 of there pot and extends into t e interior thereof in a direction tangentialto the.' interior side face of the refractory material 77, the nozzlebeing modified in cross `section ,from a circle at its rear end to anellipse at the discharge end within the fire pot in order toimpartgreater velocity to the'gas being e'ected from the same intol thefirepot.

ormed in the bottom Wall of the fire nozzle as shown in Fig. 3, is whatmaybe termed a well or receptacle 79 provided with a baille 80 extendingupwardly and inwardly from the bottom interiorv wall of the nozzle 21 atthe rear end of the well 79 over the rear portion thereof, thus'forminga hood over such portion. This baiile or hood 80 is provided with aplurality of openings 80 through the same for the pur ose of conductin ametered amount of air throu h the ba e for apurpose to be describedater. I'he metal along the edges of the well 79 is formed to provideinwardly extending flange portions 81, and received within the well 79under the i'anges 81 is an absorbent pad 82 which 'may be formed'ofsuitable fibrous asbestos mate` rial, or other suitable material, and ascreen such as 83 is rovided over the up er sur- .face of the pad)` 82for maintaining t e same in place and providinga ready passage foroil'to the pad and the gases vaporlzed 01T of the pad 82 into .thenozzle. 'As indicated in Fig. 3, the oil nozzle 49 is positionedsubstantially in line with the inner edge ofthe bae 80 so that the oilbeing discharged from the same through -the openings 5() will fall uponthe pad 82. The designl of the nozzle 'and fire pot is such that inoperation the oil from the nozzle 50 is deposited upon the pad 82 whichabsorbes the same, the heat from the fire pot is conducted back throughabsorbe thereby to be given oif inthe form of a vapor'which is picked upby the air`from the tire nozzle 21 and heats the pad 82 to a relativelhigh degreewhi'ch causes the oil thefan 25 and isV carried into thefire. pot. In o eration the [ire actually extends over the pa 82 and in'low fire operation all of the oil that enters thevre pot is in the formof vaporized gas coming solely from l-thepad 82. During high reoperation when the maximum blast of air from the fan 22 is passedthrough the'iire nozzle v21, a certain amount ofunvaporized oilparticles in the form of a mist may be carried directly into the firepot without having had the opportunty of bein de osited upon Athe pad82,

and absorbed t ere to. be laterheated and vaporizedeintogthe rm of .areadily combustible gas. YInasmuch as the pad. 82 is `of,

-asto a relatively substantial area, vthe baa is lprovided at the rearof the same in order to as may occur whenv the butterfly valve 51 issuddenly opened, -and'thus prevents ssible blowingl out of the ame aboveit. he pad 82v in t is construction not only serves'the purpose of thepilot light used in the con- Ventional oil burner system. but inaddition.

serves as the sole means of supplying oil in roduce no.

purpose is best 'determlnedby protects the pad 82 from any sudden blastsofair such.l

a vaporized vstate to the fire pot, 1t being such sitively preclude itsbeing extinguishe by any blast of ainfrom the fan 25, and such as toprovide a suicient fuel re' serve therein for continuous combustion forasubstantial period of time, fpr instance, fifteen minutes to onehalfhour, depending upon the sizeand surface area of the pad 82, after theHow of oil throu the nozzle 49 has completely stopped.- he flangeprojected into the re pot thi'ough the nozzle 21, and the combustibleixture which is carried thereby and has itdbombustion completed withinthe fire pot, because of the tangential direction-.in whichv it isintroduced into the fire pot, is caused to swirl around f the same andradually rises upwardl into ontactwith t e diaphragm 78 and t en is nusrforced upwardly through the 4central opening of t e same. The flame andgases'in assng upwardly through the diaphragm 78 erm a low pressure areadirectly over the diaphragm 78 which acts to pull the ,flame outwardlyand imparts to the 'same a iiat mushroomtype of swirl formation asindicated in Fig. 4. This Haine which may be regulated by properadustment of the but-l teriiy valve 52 and .n le valve 65, may be 11| lcontrolled so ,as to approach closeto but out of contactwith the saidwalls of the furnace 15 so asto impart thev maximum amount of heat tothe same without actual contact with it, which would otherwise act tocorrode the walls ofthe furnace with which the flame came in contact.This construction also insuresthe hea'tof the combustloncomlng 1ncontact .with the lower portion, ofthe heating surface of the furnaceinstead of; the dome thereof, as is the case in substantially las all ofthe conventional oil burner constructions, and 'as the dome usually comrises less than fty per centof the heat absor ing area l of the furnace,the importance of thisfeature will be readily recognized, and it will befurther readil nnderstod that in obtaining this form of lfame I amenabled to obtain a stack temperature of as low as 200 F. as opposed toa stack temperature of between 600 and 700 F. obtained in the usual oilburning mechanism, the saving of heat as a result of this feature beingenormous.

Under high fire conditions when the maximum amount of oil and air isbeing fed to the fire pot, a certain amount of oil from the nozzle 49,as previously described, may be carried into the fire pot in the form ofa mist of unvaporized fuel particles such as the conventionalconstructions depend upon entirely for combustion. In such a case, theseparticles being heavier than the bulk of the combustible mixture beingfed into the fire pot, and because of the rotary motion imparted to themixture by the formation and location of the lire nozzle 21, thecentrifugal force acting on the particles will throw them outwardly intoContact with the incandescent' refractory lining 77'which will quicklyvaporize the same and they will thereafter be discharged through thediaphragm 78 in the form of a vaporized gas. Thediaphragm 78 serves toprevent any of these unvaporized fuel particles from being carried abovethe lire pot inasmuch as the centrifugal force acting on the particlesconfines the path of the particles to a point in the fire pot axiallyoutwardly from the inner edge of the diaphragm 78. In forming therefractory lining 77 with the airspace 79 between the same and themetallic cup portion 76 I am enabled to heat the refractory material 77to a substantially higher temperature and degree of incandescence thanin the conventional constructions, inasmuch as the air space 79 servesas an insulation between the refractory mate rial 77 and the cup 7 6 andthereb cuts down the conduction and radiation o heat from the cupportion 76 to a minimum. It also serves as a means for allowing therefractory material 77to be brought to a point of incandescense in amuch shorter period of time than in conventional constructions, andfurther serves to hold it at such temperature for arelatively greaterperiod of time after the flame Within the fire pot has beenextinguished.

In accordance with the laws of some States,

means must be provided in apparatus of this type such that should oil inliquid form accumulate within the fire pot the flow of oil to such potwill be stopped, this being a safety provision for eliminatingossibility of an explosion due to the accumu ation of a material body ofoil. This provision is taken care of in the present invention by formingan upwardly projecting boss 84 on the floor of the cup portion 76 of there pot and of such a height as to extend into flush relationship withthe floor of the insulating material 77.

The boss 84 is shown as tapered favorably to a sealing fit and asprovided with a central opening 84 the lower end of which is screw-Athreaded for connection with the pipe 85 as indicated in Fig. 3. Thepipe 85 in turn extends forwardly out through the door 27 of the ash pit16 and terminates above the bucket 86 which is suspended from the freeend of the lever 87 which actuates the trip valve 47. In operation,should for some reason or other an excess of liquid oil accumulate inthe lire pot, the oil will pass down through the opening 84 into thepipe 85 and be drained into the bucket 86. The valve 47 is so arrangedthat when a predetermined weight of oil is drained. into the bucket 86,the weight of the oil and bucket acting through lthe arm 87 will actuatethe valve 47 to stop the flow of oil to the burner.

A safety feature best shown in Fig. 3 comprises a thermostatic switchinserted in the electrical connections leading to the solenoids 62 and 73. This switch comprises the insulated base 104, the Contact member 105,and the strip of thermostatic metal 106 supported at one end on thebinding post 107 Within the fire nozzle 21 and adjacent the open end ofthe same. The electrical current passing through the solenoids 62 and 73is adapted to pass between the binding posts 105 and 107 through thethermostatic strip 106 which is so formed that when cold or relativelycold its free end is bent outwardly out of Contact with the binding post105 and when heated straightens out and makes Contact u with the bindingpost 105 and thereby permits the passage of electricity between theposts 105 and 107. Under normal operation of theburner sufficient heatis supplied to the thern'iostatic strip from the gases burning above thepad 82 to insure contact of the tl1crmostatic strip 106 with the bindingpost 105, but if for any reason all flame should become extinguishedwithin the lire pot of the lire nozzle 21, the Strip 106 will bend awayfrom the binding post105 and thereby interrupt the flow of electricityto the solenoids and 73 and movcthe mechanism to low lire position.

The novel form of lire pot which I have provided serves to produce aflame within the furnace which much more economically coacts with theheating surface of the furnace than in the conventional constructionsand this without the employment of any mechanical spreading means of anydescription whatsoever and, further, that complete burning of all theoil particles is assured and the formation of carbon prevented.

Although I have shown in the accompanying drawings and described avariety of separate and distinct features which I have combined to forman oil burner of novel construction and distinct formation it will berecognized, of course, that various of these devices may be eliminatedunder certain conditions or ma be employed in vconnection with devices oa different type, and I do not limit myself to the employment of thesame to the specific assemblage with parts and to the exact constructionshown and described, but desire to state that formal chan esmay be madein the specific embodiment o the in- `vention described withoutdeparting from the spirit or substance of the broad'invention, the sco eof which is commensurate with the appen ed claims.

What I claim is:

l. A fire pot foroil burning apparatus having a tangential inlet andcomprising a cup-shaped member provided with .a substantiallycylindrical wall and with an inwardly extendin flange adjacent an openupper end thereo the lower surface of said flange being substantiallyflat, the upper surface of said flange bein curved outwardly andupwardly, and said ange being thinnest at its inner edge. f

2. A fire pot for oil burning apparatus comprising a cup-sha ed memberprovided with an inlet dispose to impart a whirling movement to amixture admitted therethrough and with an inwardly extending angeadjacent the o n end thereof, the upper surface of said ange bein dishedto form a low ressure area over sai flange and said flange ing thinnestat its inner edge',

I whereby to spread the flame passing upwardly therethrough. j v

3. A fire pot for oil burning apparatus comprising a cup-shaped memberhaving an inwardly extending integral annular .flange adjacent the openend thereof, the outer face of said flange being formed complementary toa part of an approximately s herical surface cup, and a refractory lininand means for introducing a combustible mixture into said cup below saidHange in a direction tangential to the interior surface of said cup. i

' 6. A tire pot for oil burning apparatus comprising, in combination, ametal cup hav-ing a tapered nozzle member integral therewith anddisposed to discharge into said spaced from the sidesthereo the spacebetween said cup and lining being sealed at the open edge of said cupand about said nozzle against the circulation of air.

WINFIELD-S. GRANT.

and the inner face of said ange being substantally flat, and means forintroducmg acombustible mixture into said member in va directiontangential thereto and below said ange.

4. A fire pot for oil burning apparatus comprising a cup-shaped memberprovided with an inwardly extending integral annular flange adj aoentthe open end thereof the surface of said llange most remote from thebottom of said cup being concave and curved outwardly and away from saidbottom, and the surface of said flange more adjacent to said bottombeing substantially dat and disposed in a plane substantiallyperpendicular. .to the axis of said cup; and means for imparting awhirling motion to a fuel mixture upwardlyadvancing past said ange.

5. A fire pot for oil burning apparatus comprising a cup-shaped memberprovided with an inwardly extending integral annular flange adjacent theopen end thereof, the surface of -said angefmost remote from the bottomof said cupbeig concave and curved outwardly and away from said bottom,the

for 4said cup

